Polymorphism of flagellin A gene in<i>Helicobacter pylori</i>

Ji, Wansheng; Hu, Jialu; Qiu, Jun-Wen; DaoRong, Peng; Shi, Bing-Long; Zhou, Shao-Juan; Wu, Kaijie; Fan, Daiming

doi:10.3748/wjg.v7.i6.783

Cited by 5 publications

(2 citation statements)

References 64 publications

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“…Based on the amino acid sequences of flagellins from 24 a-type P. aeruginosa strains, the largest number sequenced to date, we were able to identify two broad subtypes, A1 and A2. Such structural differences of flagellins have been displayed in several other bacteria, including Escherichia coli (28), C. jejuni (10), and Helicobacter pylori (13). The mechanism of flagellin polymorphism in C. jejuni was suggested to be both intergenomic and intragenomic recombination (10).…”

Section: Discussionmentioning

confidence: 97%

Sequence Polymorphism in the Glycosylation Island and Flagellins of Pseudomonas aeruginosa

et al. 2004

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A genomic island consisting of 14 open reading frames, orfA to orfN was previously identified in Pseudomonas aeruginosa strain PAK and shown to be essential for glycosylation of flagellin. DNA microarray hybridization analysis of a number of P. aeruginosa strains from diverse origins showed that this island is polymorphic. PCR and sequence analysis confirmed that many P. aeruginosa strains carry an abbreviated version of the island (short island) in which orfD, -E and -H are polymorphic and orfI, -J, -K, -L, and -M are absent. To ascertain whether there was a relationship between the inheritance of the short island and specific flagellin sequence variants, complete or partial nucleotide sequences of flagellin genes from 24 a-type P. aeruginosa strains were determined. Two distinct flagellin subtypes, designated A1 and A2, were apparent. Strains with the complete 14-gene island (long island) were almost exclusively of the A1 type, whereas strains carrying the short island were associated with both A1-and A2-type flagellins. These findings indicate that P. aeruginosa possesses a relatively low number of distinct flagellin types and probably has the capacity to further diversify this antigenic surface protein by glycosylation.Pseudomonas aeruginosa is a motile opportunistic Gramnegative bacterium that possesses a single polar flagellum. The flagellum of this organism is structurally similar to those of other Gram-negative bacteria and contains a relatively complex basal body and hook structure attached to a filament primarily consisting of the assembled flagellin subunit protein.Although the role of flagellar motility in virulence of many pathogenic microorganisms including P. aeruginosa has been well established (9,18,19), the recent discovery that flagellin is one of the most potent stimuli of the host innate immune response gives added significance to the expression of flagella in the context of infection. Flagellin-based signaling in a variety of cells is mediated by Toll-like receptor 5 (11), and in P. aeruginosa, it has been shown to be more potent than Pseudomonas lipopolysaccharide (17).The flagellin proteins of P. aeruginosa can be classified as a-type or b-type, based on their reactions with specific polyclonal antibodies and their molecular weights (1, 2, 16). The a-type flagellins are reported to be heterologous and have variable molecular masses ranging from 45 to 52 kDa, whereas b-type flagellins are essentially conserved in sequence and have an almost invariant molecular mass of 53 kDa. However, between the two types, the N-and C-terminal domains are conserved while the central domain of the a-type is said to be hypervariable, leading to antigenic or serological variations (21, 29). The a-type flagellins have been further classified into several subtypes based on their H-antigenic components (2), nucleotide sequence variations (23), or restriction fragment length polymorphisms (20).Totten and Lory first noted anomalous migration and heterogeneity of the a-type flagellins during sodium dodecyl sulfate...

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Section: Discussionmentioning

confidence: 97%

Sequence Polymorphism in the Glycosylation Island and Flagellins of Pseudomonas aeruginosa

et al. 2004

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“…As medical workers in China, we are duty‐bound to study this disease. Currently, the causes of gastric cancer have not been conclusively demonstrated, 2–5 so instead of etiological treatment, early detection of gastric cancer has become an important strategy for reduction in mortality from this disease. However, the vast majority of patients with early gastric cancer tend to have no specific symptoms, so when they go to see a doctor they are always in the advanced stage 6 .…”

Section: Introductionmentioning

confidence: 99%

Bird’s‐eye view on gastric cancer research of the past 25 years

Fan

Zhang

Chen

et al. 2005

J of Gastro and Hepatol

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This paper provides a bird's-eye view of our 25-year research work on gastric cancer, including both exploration of pathogenesis and preclinical or clinical applications of diagnosis and treatment. Although there have been achievements and reasons for applause, there are, nonetheless, more failings and teachings. Some problems that we experienced 25 years ago are still problems we have to face today. We are absolutely not singing the same old tune. Looking back makes us wiser and our way smoother. Although it is a long and arduous way to further study gastric cancer, we are willing to devote ourselves to it.

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